1. Field of the Invention
This invention relates generally to a washing apparatus and more specifically to an apparatus and method for washing small parts such as screws, nuts, fasteners, etc., and the containers utilized in handling these small parts. In the manufacture and handling of such small parts the pieces are usually carried in tote boxes. These tote boxes are typically water-tight. Prior to use, storage or shipping, the small parts must be cleaned and freed of metal chips, treated to prevent rust or storage deterioration or prepared for further processing such as painting, plating or further machining.
2. Description of the Prior Art
In prior art systems for cleaning small parts, the tote box contents are typically emptied into washing machines of varied configurations. The tote box and contents are cleaned separately, after which the parts are returned into the same or different tote boxes. Such systems generally require manual materials handling steps, which increase the time and cost of a cleaning operation.
With systems wherein the contents and tote box are cleaned separately, there is a possibility that parts from one tote box may become mixed with parts from another tote box. Such a mixture of different type parts is highly undesirable. For example, dissimilar parts may not fit into a jig fixture or die designed for other parts in the container. A parts mix, therefore, can be potentially damaging to processing equipment and can create a hazard to an equipment operator.
An example of one prior art apparatus which solves some of the above problems is disclosed in U.S. Pat. No. 3,578,002, which is assigned to the assignee of the present application. This apparatus dumps the tote box contents into a container, cleans both contents and tote box, and then returns the contents to the same tote box. The container includes a plurality of perforated cages arranged in ferris wheel fashion about a shaft. The cages are rotated about the shaft causing the contents of a tote box to empty into the perforated cage. The small parts descend to the lower part of the perforated cage, and the cage rotates into a cleaning solution bath. During rotation, the tote box is also submerged in the cleaning solution bath which simultaneously cleans both the tote box and the tote box contents. As the rotation continues, the contents are lifted from the cleansing bath and are returned to the same tote box. While this apparatus solves many of the problems associated with the early washing apparatus, the entire ferris wheel assembly must be raised or lowered into the washing tank, making this process relatively slow. Further, the ferris wheel apparatus does not lend itself readily to multi-stage cleaning operations and depends upon a soaking action to clean the parts. Also, since the small parts tend to bunch together in the container, some of the surfaces may not be exposed to the cleaning bath, resulting in incomplete cleansing thereof.
The present invention eliminates the disadvantages of the prior art small parts cleaning systems. The present invention provides an apparatus and method for quickly, efficiently, and automatically cleaning both the tote box and contents and returning the contents to the same tote box. The present invention includes a washing container onto which the tote box parts are dispersed to provide rapid and efficient cleaning of the parts by vigorous cleansing spray solutions. The present invention is also readily adaptable to multi-stage cleaning operations to include presoaking of the tote box contents.